Key Features and Technology
Lowenberg’s primary goal was to create a stamp that would be destroyed if anyone tried to soak it off an envelope or wash away the cancellation ink.
Decalcomania Process: His most famous invention involved printing the stamp design in reverse on the back of transparent onionskin paper or goldbeater's skin. The adhesive was then applied over the ink. Once stuck to an envelope, any attempt to remove the stamp would leave the ink behind, destroying the image.
Starch-Coated Paper: Another patent involved coating paper with a thick, water-soluble starch solution before printing. If washed, both the ink and the starch layer would dissolve.
Crude Designs: Many of these essays, such as the 1867 3¢ Washington (Scott 79-E8a), featured relatively crude designs compared to standard postage of the time.
Historical Context
Rejection by the U.S.: Although the U.S. Treasury Department and the National Bank Note Company tested his designs extensively, they were ultimately rejected in favour of the grilling process, which was deemed more practical for mass production.
Prussian Adoption: While the U.S. and France declined his submissions, Lowenberg’s homeland of Prussia (modern-day Germany) did accept and issue two stamps using his decalcomania process in 1866.
